Prognostic factors for the success rate of embryo freezing

52Citations
Citations of this article
14Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

To find some prognostic factors for the outcome of frozen-thawed cycles, we have retrospectively analysed all frozen pre-embryos that were thawed during 1993 and 1994 at two in-vitro fertilization (IVF) units in Sweden. Supernumerary pre-embryos were frozen from 551 oocyte retrievals and these resulted in 660 frozen-thawed cycles which lead to 623 thawed embryo transfers. The outcome of these transfers was 137 clinical pregnancies with a pregnancy rate of 22% per frozen-thawed embryo transfers. Women < 40 years of age had a higher birth rate than those ≤ 40 years, 19 and 5% respectively (P < 0.01). Transfers with two and three pre-embryos resulted in pregnancy rates of 23 and 27%, respectively, compared with 14% for transfer of one embryo. A pregnancy resulting from the initial embryo transfers had a predictive value for results of the subsequent frozen-thawed cycle. Embryo grade and cleavage stage at the time of freezing was important for the survival of the frozen-thawed pre-embryos. The pregnancy rate was not influenced by the cleavage stage, but a tendency toward a lower pregnancy rate was seen for the embryos with lower grading. To conclude, cryopreservation seems to be beneficial in women < 40 years of age, who have supernumerary pre-embryos of good quality for freezing and of which at least two can be transferred.

Cite

CITATION STYLE

APA

Karlström, P. O., Bergh, T., Forsberg, A. S., Sandkvist, U., & Wikland, M. (1997). Prognostic factors for the success rate of embryo freezing. Human Reproduction, 12(6), 1263–1266. https://doi.org/10.1093/humrep/12.6.1263

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free